Open-Topped Stackable Container

ABSTRACT

An open topped stackable container tub ( 1 ) is provided comprising side walls ( 2 ), end walls ( 3 ) and a bottom wall ( 4 ), the side walls being provided with open fork lift insertion recesses ( 5 ) along the length of the side walls in proximity to the bottom. In a preferred embodiment the bottom is provided with downwardly protrusions ( 6, 7, 8 ) wherein outer dimensions of said protrusions mate with the inner periphery ( 9 ) of the open top of the container, allowing secured vertical stacking of two or more of said containers.

TECHNICAL BACKGROUND AND PRIOR ART

The present invention relates to containers or tubs suitable for storing and transporting fish and/or other food products. Such containers molded in plastic are commonly used on board vessels and in fish processing facilities as well as for transporting fish. Typically the bottom of such fish tub containers is shaped like a pellet to facilitate fork lifting of the tubs. When such containers are filled to the rim with slippery material such as fish and ice the top layer may easily glide off and out from the container, during transportation on a vessel or truck. This can happen also if containers are stacked on top of each other, as the top layer material in a lower container may still escape through the open space between the top rim of the container and the pellet-shaped base of an upper container stacked on top of it. The space between stacked container als mean that there is void space left between the containers which means that some space is not being utilised within a limited cargo space (e.g. on board a truck or vessel) which is filled with containers.

SUMMARY OF INVENTION

The present invention provides a novel type of fish tub container which can be readily stacked to create a substantially tight closure on a lower container, preventing loss of material and enhancing the overall insulation of the containers. The container has larger inner volume relative to its overall outer dimensions as compared to conventional containers and thus enables more efficient use of storage space, e.g., in cargo compartments of vessels. Additionally, the container allows flexible handling by a fork lift. The container is provided with recesses along the bottom of side walls of the container, allowing fork lifting and tumbling and rotating the container on a fork lift such as for washing, emptying, etc.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows a bottom perspective view of a preferred container tub of the invention.

FIG. 2 show a top perspective view of a preferred container tub of the invention.

FIG. 3 shows a side view, an end view and a top view of container tub. 3 a shows a side view (left) of a side wall 2 of the container and a cross-section (right) through the section A-A illustrating clearly the cross-section of the insertion recesses 5 and shoulders 12. 3 b shows an end view (left) of an end wall 3 of the container and a cross-section through the section A′-A′. 3 c shows a top-view of the container. Note that the marked in dimensions are only meant to illustrate a preferred embodiment; the embodiment illustrated in the drawings is not limited to the exact size and dimensions indicated.

FIG. 4 shows another embodiment, where the side walls 2 (with the recesses 5) are shorter than the end walls 3. 4 a shows a bottom view, 4 b is an end view cross-section of the section B-B, 4 c is an end view showing an outer end wall 3, 4 d is a side view cross-section through the section A-A, 4 e is a side-view showing a side wall 2 and 4 f is a top view. Note that the drawings are not drawn to scale.

FIG. 5 shows yet another embodiment of a container with shorter side walls 2 than end walls 3.

FIG. 6 shows a side view, an end view, top view and cross-section of the container shown in FIG. 5. 6 a shows an end view, 6 b a side view, 6 c the cross-section through the section A-A and 6 d is a top view.

DETAILED DESCRIPTION

The invention provides an open-topped stackable container 1 which comprises side walls 2, end walls 3 and a bottom wall 4. The side walls are provided with open fork lift insertion recesses 5 along the length of the side walls in proximity to the bottom, of sufficient width/depth and height to allow insertion and secure holding by a conventional fork lift. Preferably the recesses have a width (depth) in the range, of about 7-20 cm, such as the range of about 7-12 cm such as preferably about 10 cm. In certain embodiments described in more detail below extra deep recesses may be advantageous, such as having a width in the range of about 12-20 cm, such as in the range of about 15-20 cm. The height must be sufficient to readily accommodate a lift fork of conventional thickness, preferably the height of the recesses is in the range of about 5-15 cm or the range of about 5-10 cm, such as in the range about 5-7 cm or the range about 7-10 cm, including about 4 cm, 5 cm, 6 cm, 8 cm or 10 cm. Still, the recesses should not be too big as that would unnecessarily reduce the internal volume of the container.

The container is of a generally rectangular shape when looking from a top-view, and can have side walls 2 which are longer than the end walls, as is illustrated in the embodiment shown in FIG. 3, or alternatively side walls 2 which are shorter than the end walls, as illustrated in FIGS. 4-6. In yet a further embodiment, the side walls can be the same length as the end walls, creating essentially a square container.

In a preferred embodiment, the bottom of the container is provided with downwardly protrusions 6, 7, 8. Said protrusions are preferably arranged such that the outer dimensions of said protrusions mate with the inner periphery 9 of the open top of a second container, thereby allowing secured vertical stacking of two or more of said containers. The protrusions provide support feet to the container and are preferably of sufficient height to allow insertion of a lift fork underneath the container, in between the protrusions, for lifting the container. Typically, the container has at least a protrusion element in each corner of the bottom (corner protrusions 6) and preferably also a protrusion element centrally in between adjacent corner elements (center end protrusions 8 and/or center side protrusions 7). Preferably, the protrusions are arranged such as to provide for fork lift slots 10 parallel with the side walls and preferably additionally or alternatively fork lift slots 11 parallel with the end walls of the container.

As mentioned above, it is an advantage of the present invention that upon stacking two containers one on top of each other the upper container creates a substantially tight lid for the lower container. Additionally, in the embodiments where the containers are provided with the mentioned bottom protrusions the stacking is secure such that the upper container cannot readily slide off the lower container as the protrusions of the upper container extend into the lower container and mate with the inner periphery 9 of the open top of the lower container.

The recesses inflict shoulders 12 inside the container, along the interior side walls on the bottom of the container, said shoulders are defined by a shoulder side 13 and a shoulder top surface 14. The shoulders can be advantageously used for inserting a loose bottom plate resting on the shoulders; for instance, a perforated bottom plate can be inserted and laid on the shoulders for rinsing and/or more effective draining of product stored in the container.

The container preferably has at least one hole 17 adjacent to the bottom providing a drain for draining liquid of the container. The hole is preferably sealable with a matching plug and can in certain embodiments also be used to connect a hose to the container or a pipe, e.g. as part of a cooling system. Preferably, there are two or more holes, e.g., in opposing corners of the container or in every corner of the container. Said at least one hole can suitably extend through a shoulder side of the container and is preferably circular. In the embodiment shown in FIG. 2 the bottom of the container has guiding grooves 18 parallel with the end walls 3, that can receive liquid, e.g. melting water, and guide to the drain hole(s).

In a useful embodiment the plug to seal the drain hole is provided with a sealing surface which mates with a sealing surface in the hole within the periphery of the hole closest to the surface of the inner wall, such that when the hole is plugged, the plug creates a substantially flat surface where water and dirt can not reach from the container into any gap or crevice between the hole and plug (e.g. in threads of the hole).

The container has in one embodiment bevelled corner surfaces 15, the upper ends of which comprise outwardly extending corner pieces with handles/slits 16 that can be used for lifting said container by hooks.

The container is in a useful embodiment configured such that liquid that drains from the drain hole of an upper container does not substantially leak into a lower container onto which the upper container is stacked. This can be suitably implemented by forming the distal ends of the insertion recesses such that the lower surface of the recess (the surface 19 which form a flat board surface in the embodiment shown in FIG. 2) has a distal edge 21 that reaches sufficiently distally such that any liquid dripping of the edge will not drip into the lower container and preferably is shaped such that the liquid drips through the handle/slit 16. The surface 19 may have a slanting distal end 20 to guide draining liquid towards the distal edge. In one embodiment the distal edge has a notch 22 to further guide the draining liquid and may as well have a corresponding notch 23 in the handle/slit 16.

FIG. 4 shows a slightly different embodiment than in FIG. 2 or 3. Also in this embodiment, the side walls 2 are shorter than the end walls 3. The side walls 2 have recesses 5, which in this particular embodiment have more depth than seen in FIG. 2 and 3. The container is provided is provided with four drain holes 17 located on the end walls close to the bottom, adjacent to the ends of the recesses 5. The inner surface of the bottom wall 4 has a center ridge 26 creating a slight inclination away from the center ridge such that any liquid runs down towards the grooves 18 and drain holes 17.

This embodiment shows another configuration for draining of liquid that leaves the containers; on the end walls are created vertical drain grooves 25 which overlap with the drain holes 17. At the upper end of the drain groove is a recess 24 in the outer top edge of the end wall, in roder to guide draining liquid dow the guiding groove and if the container is stacked on top of another container, the draining liquid that runs down the guiding groove is directed to the corresponding guiding groove of the adjacent lower container.

The depression 27 on the end wall is an optional feature, intended for an RFID tag (radio, frequence identification tag, also referred to as transponder).

It will be understood that the present invention is not limited to containers or bins of any certain size and can have substantially the same or similar size as conventional bins, e.g. with an internal volume in the range of about 150-1200 L. This includes relatively small bins suitable for manual handling and/or in small contained spaces, e.g. on board small vessels, such as in the range of about 150-350 L including the range of about 150-250 L or about 200-250 L. Intermediate sized bins may as well be produced in accordance with the invention, e.g. in the range of about 350-600 L such as in the range of about 350-500 L or in the range of about 400-500 L, including about 400 L, about 440 L or about 460 L. The invention comprises as well larger bins, such as in the range of about 700-1200 L, including, about 750 L, 800 L, 1000 L or 1200 L. It will be particularly appreciated that for smaller bins, e.g. in the range of about 250-660 L the volume gain as compared to conventional tubs with “pellet” shaped bottom will be relatively more than for larger tubs. Hence, in certain embodiments, the container tub has a volume in the range of about 250-660 L, such as in the range of about 350-500 L, including about 400 L, 440 L, 460 L or 480 L.

Commercially available conventional 440 L fish tubs, produced e.g. by the present applicant have a total height of about 58 cm. A tub of the present invention with the same volume of 440 L has a height of about 48 cm, hence saving about 20% space. Containers of the invention have in some embodiments a total height in the range of 35-65 cm, including the range of about 40-60 cm, such as about 45 cm, 48 cm, 50 cm or 55 cm.

Containers of similar size as the embodiment shown, in FIGS. 4 and 5, with long end walls which are longer than the width a conventional fork lift, e.g. about 1200 mm, are found particularly advantageous, as such wide end walls allow for a conventional fork lift to remove a first vertical row of containers from a large stack of containers and subsequently drive into the void in the stack to remove the next vertical row which was immediately behind the first vertical row. This gives increased flexibility to move the container in a working area such as a storehouse, stockroom or the like. In these embodiments of the container it may useful to have extra deep recesses 5 which reduce the width of the container measured between the recesses 5 (i.e., the width which dictates the necessary width between the two prongs of the lift fork).

The container of the invention is preferably molded from a thermoplastic polymer material, e.g. polypropylene, polyethylene (including LLDPE, LDPE and in particular HDPE), polyamide (Nylon), polystyrene, polyurethane, polyvinylchloride, acetal, polyphenylene sulfide, polyesters, and the like. Other polymer materials may as well be used in certain embodiments, such as acrylonitrile butadiene-styrene (ABS) and other copolymers (acetal copolymers).

The containers are typically molded by conventional means well known to the skilled person. Preferred methods include rotomolding, although it is contemplated that other methods may as well be used such as injection-molding, compression molding or extrusion blow molding, and other conventional methods may as well be used.

For added insulation the container can comprise a double-wall outer shell surrounding an inner core. The inner core preferably comprises a material selected from polyethylene foam and polyurethan foam. A double-walled container of the present invention can be produced by rotomolding in order to mold the outer wall shell and subsequently the inner core material may be introduced by injection before the other wall shell is sealed off. The container of the present invention can however also be of single-walled type which can be produced e.g. by rotomolding. 

1. An open topped stackable container comprising side walls, end walls and a bottom wall, the side walls being provided with open fork lift insertion recesses along the length of the side walls in proximity to the bottom, wherein upon stacking two containers one on top of each other, the upper container creates a substantially tight lid for the lower container.
 2. The container of claim 1, wherein said recesses create shoulders on the inner bottom of said container, along the Inner sides of said side walls, each of said shoulders having a shoulder side and a shoulder top surface
 14. 3. The container of claim 1 with a general rectangular shape seen from a top-view, with said side walls being longer than said end walls.
 4. The container of claim 1 with a general rectangular shape seen from a top-view, with said side walls being shorter than said end walls.
 5. The container of claim 1 with a general square shape seen from a top-view, with said side walls being essentially the same length as said end walls.
 6. The container of claim 1, the bottom of said container being provided with downwardly protrusions, wherein said downwardly protrusions are arranged such as to provide for fork slit slots under the container when said container is resting on a fiat surface, said slots being aligned with the side walls of the container.
 7. The container of claim 1, the bottom of said container being provided with downwardly protrusions, wherein said downwardly protrusions are arranged such as to provide for fork slit slots under the container when said container is resting on a flat surface, said slots being aligned with the end walls of the container.
 8. The container of claim 6, the bottom of said container being provided with downwardly protrusions, wherein outer dimensions of said protrusions mate with the inner periphery of the open top of the container, allowing secured vertical stacking of two or more of said containers.
 9. The container of claim 1 having bevelled corner surfaces, the upper ends of which comprise outwardly extending corner pieces with handles/slits that can be used for lifting said container by hooks.
 10. The container of claim 1 having at least one drain adjacent to the bottom wall for draining liquid from said container.
 11. The container of claim 10, wherein said at least one drain comprises a hole extending through said shoulder side.
 12. The container of claim 10, wherein said at least one drain comprises a hole extending through one of said end walls.
 13. The container of any of claims 1 having an internal void volume in the range of about 250-660 L.
 14. The container of claim 13 having a total height in the range of about 35-65 cm.
 15. The container of claim 1, produced from a polymer material comprising a polymer selected from polyethylene, including LLDPE, LDPE and HDPE, polypropylene, polyamide, polystyrene, polyurethane, polyvinylchloride, acetal, polyphenylene sulfide, polyester, acrylonitrile butadiene-styrene and mixtures thereof.
 16. The container of claim 1, comprising a single-walled container.
 17. The container of claim 1, comprising a double wall outer shell surrounding an inner core.
 18. The container of claim 17, wherein said Inner core comprises a material selected from polyethylene foam and polyurethane foam. 